FOREX COMPUTER CORPORATION
FOREX 486 (REV. VL3H)
|
Processor |
80486SX/80487SX/80486DX/80486DX2/P23T/P24T |
|
Processor Speed |
20/25/33/40/50(internal)/50/66(internal)MHz |
|
Chip Set |
Forex |
|
Video Chip Set |
None |
|
Maximum Onboard Memory |
32MB |
|
Maximum Video Memory |
None |
|
Cache |
64/128/256KB |
|
BIOS |
AMI |
|
Dimensions |
260mm x 220mm |
|
I/O Options |
32-bit VESA local bus slots (3), green PC connector |
|
NPU Options |
None |
|
CONNECTIONS | |||
|
Purpose |
Location |
Purpose |
Location |
|
Turbo LED |
J6 |
External battery |
JP1 |
|
Speaker |
J7 |
Green PC connector |
JP14 |
|
Turbo switch |
J8 |
Green PC LED |
JP15 |
|
Power LED & keylock |
J9 |
32-bit VESA local bus slots |
SL1 – SL3 |
|
Reset switch |
J10 | ||
|
USER CONFIGURABLE SETTINGS | |||
|
Function |
Label |
Position | |
|
PQFP CPU enabled |
JP5 |
Open | |
|
PQFP CPU disabled |
JP5 |
Closed | |
|
» |
CMOS memory normal operation |
JP6 |
Unidentified |
|
CMOS memory clear |
JP6 |
Unidentified | |
|
Green PC disabled |
JP13 |
Open | |
|
Green PC enabled |
JP13 |
Closed | |
|
Green clock speed select 8MHz |
JP16 |
Pins 2 & 3 closed | |
|
|
Green clock speed select 16MHz |
JP16 |
Pins 1 & 2 closed |
|
DRAM CONFIGURATION | ||
|
Size |
Bank 0 |
Bank 1 |
|
1MB |
(4) 256K x 9 |
None |
|
2MB |
(4) 256K x 9 |
(4) 256K x 9 |
|
4MB |
(4) 1M x 9 |
None |
|
5MB |
(4) 256K x 9 |
(4) 1M x 9 |
|
8MB |
(4) 1M x 9 |
(4) 1M x 9 |
|
16MB |
(4) 4M x 9 |
None |
|
20MB |
(4) 1M x 9 |
(4) 4M x 9 |
|
32MB |
(4) 4M x 9 |
(4) 4M x 9 |
|
CACHE CONFIGURATION | |||
|
Size |
Bank 0 |
Bank 1 |
TAG |
|
64KB |
(4) 8K x 8 |
(4) 8K x 8 |
(1) 8K x 8 |
|
128KB |
(4) 32K x 8 |
None |
(1) 8K x 8 |
|
256KB |
(4) 32K x 8 |
(4) 32K x 8 |
(1) 16K/32K x 8 |
|
CACHE JUMPER CONFIGURATION | |||
|
Size |
JP8A |
JP8B |
JP8C |
|
64KB |
Pins 2 & 3 closed |
Pins 1 & 2 closed |
Pins 2 & 3 closed |
|
128KB |
Pins 1 & 2 closed |
Pins 2 & 3 closed |
Pins 1 & 2 closed |
|
256KB |
Pins 1 & 2 closed |
Pins 1 & 2 closed |
Pins 1 & 2 closed |
|
CPU SPEED SELECTION | |||
|
Speed |
JP7A |
JP7B |
JP7C |
|
20MHz |
Open |
Closed |
Closed |
|
25MHz |
Closed |
Open |
Open |
|
33MHz |
Open |
Open |
Open |
|
40MHz |
Closed |
Closed |
Open |
|
50iMHz |
Closed |
Open |
Open |
|
50MHz |
Open |
Closed |
Open |
|
66iMHz |
Open |
Open |
Open |
|
CPU TYPE SELECTION | ||||
|
Type |
JP2 |
JP3 |
JP4 |
JP12 |
|
80486SX |
Pins 2 & 3 closed |
Pins 2 & 3 closed |
Pins 2 & 3 closed |
Pins 1 & 2 closed |
|
80487SX |
Pins 2 & 3 closed |
Pins 1 & 2 closed |
Pins 1 & 2 closed |
Pins 1 & 2 closed |
|
80486DX (PQFP) |
Pins 2 & 3 closed |
Pins 2 & 3 closed |
Pins 2 & 3 closed |
Pins 1 & 2 closed |
|
80486DX (PGA) |
Pins 1 & 2 closed |
Pins 1 & 2 closed |
Pins 1 & 2 closed |
Pins 1 & 2 closed |
|
80486DX2 |
Pins 1 & 2 closed |
Pins 1 & 2 closed |
Pins 1 & 2 closed |
Pins 1 & 2 closed |
|
P23T |
Pins 2 & 3 closed |
Pins 1 & 2 closed |
Pins 1 & 2 closed |
Pins 1 & 2 closed |
|
P24T |
Pins 1 & 2 closed |
Pins 1 & 2 closed |
Pins 1 & 2 closed |
Pins 2 & 3 closed |
|
CPU TYPE SELECTION (CYRIX ONLY) | |
|
Type |
JP20 |
|
CX486DX |
Open |
|
CX486DX2 |
Closed |
|
VL BUS WAIT STATE SELECTION | |
|
Setting |
JP10 |
|
0 |
Pins 1 & 2 closed |
|
1 |
Pins 2 & 3 closed |
|
VL BUS SPEED SELECTION | |
|
Speed |
JP11 |
|
<= 33MHz |
Pins 1 & 2 closed |
|
>33 MHz |
Pins 2 & 3 closed |